If it is a critical joint (minimal discontinuities) you should scrape the weld area with a carbide type cutter prior to fitup and welding. I use a paint scraper from McMaster that has replaceable blades. There is an art to it, as you do not want to leave fine shavings on the weld surface before welding. I always blew off the weld area with argon or nitrogen before I welded.You want to use helium for your shielding gas, it will increase your heat input. You want DC- tig, or if you have a welder with a pulse option use that. I had good results on aluminum with DC- pulsing with a 50% on time and 50% lower amp amount.

Beyond that, look for info from Lincoln electric, Miller electric and the web...

Just wanted to say thanks for always being an upstanding guy. In my mind your fabrication work is what made armadillo armadillo. While the work John is doing on VR now is cool and will largely impact the way we interact in the future. It is just not on the same scale of importance as the work you guys were doing.

Would you ever work with him again if he made it his sole endeavor? Was that about the time that Ben Brockert left as well? I am not even sure what he is doing now.

In any case AA showed the way for the next generation of effort in space. Thank you for that. And thank you for getting the guys to open the hanger for the last LLC flights with scorpius.

Would you ever work with him again if he made it his sole endeavor? Was that about the time that Ben Brockert left as well? I am not even sure what he is doing now.

~Daniel

Ben and I left around the same time mostly for the same reasons.Would I go back to Armadillo? Most likely not...I would love for things to be like when I first started with AA because it was magical, seemed like anything was possible from our little team. I loved working there, even unpaid, as it was such a creative environment. We could move and change around problems quickly, and we got results. It felt important.It slowly changed though. Instead of taking a month to build and start flying a rocket, it was taking 6-12 months. We did some really beautiful very finished assembly work. But beautiful work means nothing if you go crash it on its first or second flight. I was frustrated at the end because we had so many problems that were caused because of a lack of operational discipline. Mundane stuff like not charging the batteries after a flight and or leaving the computer on and coming in the next day and the battery pack was killed, or things on the post flight checklist not getting taken care of. We got in a state of not really documenting things consistently, and would have repeat errors. It was tough to leave, but I really saw no ways to make the team realize we had problems that needed addressing, and that my criticism was pretty much not going anywhere.Would I go back? It would take really big changes for me to want to. I do not see John starting back at it either, his posts on the internet have shown he is excited about his current endeavor. While I am sure he still thinks about space, his plate is pretty full with family, Oculus and Id.I do miss it though.

Thanks, I think that summerizes the situation well. It would have been nice from a fan perspective if a couple of guys with a hobby had been able to do some of the things that spacex is not doing with their grasshopper. I don't suppose that large of a company holds much interest for you. But their welding needs are huge. It is neat to look at the joins on some of the large structures they have put together.

On a side note, did you ever get your prius or do an electric conversion? I have a cousin that converted a honda crv. I still need to build a garage so I can do that sort of thing.

James, Ben, and all the others, thanks! It's been great following your progress, especially in the early years. You and Armadillo deserved a better ending than this, but unfortunately the whole point of commercial space is that mistakes get punished and crashed rockets don't pay the bills. Still, Armadillo was one of the pioneers of NewSpace. You blazed a trail for others like Masten and Copenhagen Suborbitals to follow, and even if Armadillo disappears, its legacy lives on and you'll have a spot in the history books for sure.

_________________Say, can you feel the thunder in the air? Just like the moment ’fore it hits – then it’s everywhereWhat is this spell we’re under, do you care? The might to rise above it is now within your sphereMachinae Supremacy – Sid Icarus

On a side note, did you ever get your prius or do an electric conversion? I have a cousin that converted a honda crv. I still need to build a garage so I can do that sort of thing.

An electric car or hybrid is interesting but a pretty big investment in money and time, both of which I have little. I might consider it eventually but for now I have to keep it low cost.

I decided to go a different route, and bought a diesel truck (fixer upper) and have got it tuned up and running well. I want to run waste vegetable oil in it. I am collecting parts for a centrifuge, and have an area for processing and storage.

I still need to get the WVO though, and have tried a few local places but as of yet I have not found anyone that wants to give their old oil away. All are selling it to WVO collectors.

My Teammate Stewart has a WVO Truck and it is very cool indeed to run WVO. It has gotten harder to find oil. They used to be charged for waste oil and now they can get paid for it. We have a WVO facility here for sure. Our Gen can run on it too. It's a good backup in fact we are considering growing sunflowers and making use of the oil. We did a little test patch and it works so yeah we wont be without fuel.I did several Mercedes conversions back when I still did mechanic work before there where kits. In fact that's kind how I meet Stew at a rocket launch. We chatted over his truck for a while.

James I have a project you may have an interest in doing some fab work on? Have you ever heard of a farnsworth fusor? I've recently gathered up some equipment to construct one. I'd like to fabricate a SS chamber to run some experiments. I know the fusor is fringe science but I have an interest in that direction for propulsion. It's not a main project but one I'd like to dabble in on the side.

A fusor is an ideal project for someone with your experience as a machinist. There is also no need for you to concern yourself with fusors as “fringe” science. Fusors have been available commercially for a number of years as neutron sources. Their operating principles are well understood and well documented.

Well playing with a fusor is considered a waste of time in many circles. I'm going to try what I may to increase it's output. I'm looking at resonant chamber designs and cyclotronic resonance and possible other means of pumping the ions and electrons. I grew up with accelerators (my father) and electrostatic confinement is the only light weight solution available. I'm really not interested in fusion so much in it's self I'm interested in enough heat to power rockets. Like project pluto style rockets. The main part of the function is already known. We just need a better source and that's what I'm working on a better source not fusion I'm an explorer and I'm going to explore the fusor. All I can really say.

Fusors have never been (and almost certainly never will be) practical energy sources. Without getting technical, there is too much “interference” going on during the reaction. On the other hand, they are probably the cheapest, simplest and most reliable means for producing nuclear fusion reactions for research and as a neutron source.

The slightly misnamed “Focus Fusion” reactors are probably the most promising. I say “slightly” misnamed because even though these very simple reactors are easily capable of producing fusion reactions using hydrogen, the ultimate goal is actually an extremely efficient fission reaction using an abundant isotope of boron as the fuel. Yes, you read that right, the very same reactor can produce fusion or fission reactions depending on what you put in it.

A machinist with your experience can certainly make one. However, even though neither the fuel (boron) nor the waste (helium) is radioactive, you will be dealing with X rays and some neutron radiation produced by the reaction, so proceed wisely.

I'm working on a liquid fueled rocket project for an academic team & I have some fabrication questions.

Did you have to heat treat & x-ray the tanks on the quads, mods, or early tube rockets?

No- They were 5000 series and were work hardening, and we did not have Russ's dental xray machine up yet. Those tanks got visual inspections where we could at first. In the end I made up a small cheap camera for internal inspections of the root welds. We started using xray in the last two rockets when we went to a 6061 aluminum and were heat treating to a T6 on the longitudinal weld. It was necessary to find any discernible discontinuities (such as porosity or cracking). The tanks were so thin that anything would cause a stress riser and they would break prematurely.

Andy25 wrote:

How did you align all the sections on the tube rockets?

Very carefully.STIG A was tacked and welded horizontally, and it was really difficult aligning the lox and fuel tanks and bulkheads during tacking. There was a small amount of mis-alignment from end to middle (1/8" to 1/4") between the lox and fuel tanks (like it was bent), but the rocket flew well. Russ made all of the other bulkheads using the cnc lathe so you could just screw the sections together.The bulkheads on all stigs were cnc milled and the tanks on the last two also had the ends cut off on the cnc lathe. All I had to do was make sure the bulkheads were square against the tanks during welding. I found it easier to tack the bulkheads with the tanks vertical with gravity holding them together. The lox/fuel tank was about 14 feet and just barely stood up in our shop. I welded the assembly horizontally though.

Andy25 wrote:

Were the sections welded together, or secured with those screws I can see around the circumference of the bulkheads?

They were screwed together on all of the sections except for the fuel and lox tank. Those were welded together with a single interconnected bulkhead.

Andy25 wrote:

Can you briefly describe your LOX cleaning process for the tanks? Did you send the big tanks out to be professionally cleaned?

We did all of our tank work internally. Our tanks were always pretty dirty from the spinner or roller, I was amazed how dirty they would come.Dish soap and hot water wash. Scrub out with a 3-M abrasive pad. Follow with a pressure wash rinse. Repeat if necessary.Fully wipe out all internals with Acetone and clean rags, until you wipe and still have a clean rag. I also wiped down the outside with acetone or alcohol to clean it up.Prep all weld areas to your requirements, then your ready to weld.

Andy25 wrote:

How many tanks or test articles did you burst test before you decided "Okay, we're confident this fabrication technique and/or material will produce flyable tanks"?

We would usually burst one tank, but we had plenty on the last stig tanks. I welded 4 different burst tanks and went through a bunch of changes to get to 45 ksi. In the end I scrapped using AC Tig welding and went with Pulsed DC- Tig welding per the recommendations of a friend. It was really amazing. Changed the properties of the welds completely. I went from a two pass weld that usually had a lot of repair work necessary to a single pass that was pretty good and didn't need much work after, if any (the thickness was .210")